The aim — to evaluate blood flow parameters in patients with thrombosis inferior vena cava system depending on the treatment method.Materials and methods. The article presents the evaluation of hemodynamic parameters in 665 patients with different forms of deep thrombosis inferior vena cava system. The patients were divided into the following groups, according to the treatment method. The first A group consisted of 380 patients which underwent an open full or partial thrombectomy with or without surgical prophylactic of pulmonary thromboembolism. The first B group consisted of 50 patients which underwent the combined treatment with surgical prophylaxis of pulmonary thromboembolism. The second group included 235 patients which received only the conservative therapy. The laboratory and instrumental methods: ultrasound duplex scanning, X­ray phlebography, computer tomography, radionuclide fleboscintigraphy and echocardioscopy were used to carry out the study in patients. The combined treatment included regional thrombolytic therapy and a cava­filter implantation (n = 31) or surgical thrombectomy followed by intraoperative regional thrombolytic therapy (n = 19). All patients received anticoagulant, infusion­anesthetic and compression therapy regardless of surgical treatment.Results and discussion. The disabsorption of large venous collectors in the first group with partial thrombectomy resulted in a considerable increase in blood volume, whereas undergoing the radical thrombectomy recovered the blood volume back to normal values. The average transport time through the deep veins of shin and hip decreased from 53 — 68 s tо 7 — 12 s and tо 11 — 18 s in case of radical and partial thrombectomy, respectively. The linear blood speed increased from 1 — 3 сm/s tо 9 — 18 сm/s and 4 — 9 сm/sеconds in case of radical and partial thrombectomy, respectively. The load index increased from 1 — 2 to 2.8 — 3.4 and 2.2 — 2.8 in case of radical and partial thrombectomy, respectively. In the second group of patients, the average transport time after treatment was 22 — 32 seconds, the linear blood speed — 2 — 6 cm/sec, the load index — 1 — 1.5. The results of the blood renewal after the combined treatment in the first B group took an intermediate position between radical and partial thrombectomy: the average transport time is 9 — 14 seconds, the linear blood speed — 7 — 11 cm/sec and the loading index — 2.3 — 3.0. Any signs of right heart overload and symptoms of «stealing» of the peripheral arterial channel were not detected while forming an arteriovenous fistula with diameter of up to 4 mm. We found that the completion of hardware cavaplication, after thrombectomy from the inferior vena cava, did not aggravate the venous blood return to the heart.Conclusions. After the partial thrombectomy and combined treatment the surgical renewal of venous trunk permeability improved the venous blood flow, and with radical thrombectomy — restored it back to normal values. With conservative treatment, the venous blood flow did not restore due to pronounced signs of chronic venous insufficiency.